Hi, I've set up haproxy in a docker swarm environment to balance between several servers. The server task (let's call it foosrv) are configured using docker's `replicate` directive to run on multiple nodes, and as such, I don't have hostnames or IP addresses until runtime. Luckily, the docker overlay network provides a handy DNS record which facilitates finding my foosrv tasks.
A DNS lookup of `tasks.foosrv` resolves to an array of IP addresses for each of my replicated foosrv tasks. Seems like a perfect fit for the server-template directive, and it is. The wrinkle is, I'm not sure how exactly to use the params* in this scenario. According to the documentation, `server-template` takes all the same params as `server`. Some of those params though, require an argument which would depend on the actual backend server. In my case, I need to configure sticky sessions using the cookie param which requires you to pass a value. Based on reading the docs it looks like it would look something like this: ``` server-template srv 3 tasks.foosrv:80 check cookie foocookie insert # would be equivalent to: server srv1 10.0.0.1:80 check cookie foocookie insert server srv2 10.0.0.2:80 check cookie foocookie insert server srv3 10.0.0.3:80 check cookie foocookie insert ``` As you can see the entire group shares the same cookie value, which doesn't work for my purposes as the replicas have no shared state. Is there any ability to add some sort of template variable based on the `num`? Some other way to accomplish what I need? Thanks -- Uri Please consider the environment before printing this message. http://wwf.panda.org/savepaper/
